A slit lamp, also called a biomicroscope, is used for examining a human eye. The slit lamp includes a high-intensity light source that can be focused to shine a thin sheet of light into the eye for examination of the anterior and posterior segments of the eye. A slit-lamp examination provides stereoscopic magnified view of the eye structures in detail, enabling anatomical diagnoses to be made for a variety of eye conditions. One type of slit lamp is described in U.S. Pat. No. 6,283,596 while another type is described in U.S. Pat. No. 7,549,748.
FIG. 1 shows a partial view of a conventional slit lamp 10 that moves fore-aft and side-side relative to a surface 12, such as a platform or table. The slit lamp 10 moves in forward or aft translational direction 13 on an axle 14, which is coupled to wheels 15 that are configured to mesh or engage with a track 16. Accurate positioning of the slit lamp 10 is generally achieved with a joystick 17. The wheels 15 may be covered by end caps 18, which may or may not include the tracks 16. The end caps 18 may be fixed to the stationary surface 12. When the slit lamp 10 is not being used for an eye examination it may be secured to the axle 14 with a thumbscrew 20, which in turn prevents movement of the slit lamp at least in the fore-aft translational direction 13 and in a side-to-side translational direction 22.
Before an examination, the slit lamp 10 may be moved with the platform 12 to allow the patient access to an examination chair. Once seated, the slit lamp 10 may be adjusted for the particular patient. Because a base 24 of the slit lamp 10 is easily movable relative to the platform 12, the slit lamp 10 is generally locked into a static position on the platform 12 to prevent damage to the delicate slit lamp optical devices.
Thus, before and after each examination, the doctor usually has to manually manipulate the thumbscrew 20 to secure the slit lamp 10 in a desired position. Depending on the number of patients seen by the doctor, it may be necessary to manually manipulate (e.g., loosen or tighten) the thumbscrew 20 over thirty times in a single day. This repetitive task can fatigue the doctor's hand, and if forgotten may increase the likelihood for damage to or undesired movement of the slit lamp 10.